This proposal addresses two major needs of Pediatric Intensive Care. A). PICUs need a reliable, rapid, and quantitative assessment of functional status for large morbidity studies. Current methods are too time consuming and/or not applicable to infants and young children. Aim 1 is to validate a rapid and reliable measure of functional status applicable to all PICU ages and suitable for large morbidity studies. The Functional Disability Scale (FDS), a new assessment tool (10 domains with 42 objective, quantitative, easily &rapidly assessed items) has excellent pilot data. The FDS will be validated against the Vineland Adaptive Behavior Scale (VABS) and revised to better represent the relative severity of the individual items Linear regression analysis will utilize 364 patients for estimation and 121 for validation. Classification matrices will be used to choose a cutpoint for low functional status for use in Aim 2. 200 of these patients will have 6-month and 12-month telephone follow-up for FDS determination, enabling us to examine the relationship between hospital discharge status and 6 and 12 month status. B) PICUS have excellent severity measures calibrated to mortality, but there have been no serious efforts to relate ICU physiologi instability to morbidity development. Aim 2 is to develop a predictor of 3 PICU outcome states: death, survival with low functional status, and survival with adequate functional status. This will enable long-term functional status studies and costs, new quality assessments methods, and improved risk adjustment. Pilot data is very encouraging. This method would be a paradigm shift in severity of illness studies. Trichotomous logistic regression analysis will be used to develop the predictor (3800 for estimation, 1267 for validation). Independent variables include PRISM III, diagnoses, and other case-mix variables. Performance assessment will include overall performance assessment, AUC's, goodness-of-fit, and classification matrices.